Grate for boiler-furnaces



(No Model.) 2 Sheets -Sheet 1.

' O. H. HOLT GRATE FOR BOILER FURNACES.

No. 312,472. Pa;t'ented Feb. 17, 1885.

Fig.1.

\IVITNESSES: INVENTOR:

N PETERS, PholwLilhogmpMr. Washington. 01c.

(No Model.) 2 Sheets-Sheet 2.,

G. H. HOLT.

GRATE FOR BOILER FURNACES.

Patente% Feb. 17, 1885.

INVENTOR:

ATTORNEY.

WTNESSESZ 'tlnrrnn Srarins ArnN'r OFFICE,

CHARLES H. HOLT, on PHILADELPHIA, rEnNsYLvANiA.

GRATE FO R BOlLER-FU RNAC ES.

SPECIFICATION forming part of LetteraPatent No. 312,472, dated February 17, 1885.

Application filed November 1'7, IP82. (No nndel.)

To aZZ whom it may concern.-

Be it known that I, CHARLES H. HOLT, a subject of the Queen of Great Britain, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and, useful Improvement in Grates for BoilerFurnaces, &c., which improvement is fully set forth in the following specification and accompanying drawings, in which- Figure 1 is a front view, partly sectional, of the grate embodyingmy invention. Fig. 2 is a rear view thereof. Fig. 3 is a longitudinal vertical section thereof;

Similar letters of reference indicate corresponding parts in the several figures.-

My invention relates to improvements in an endless grate of the order known as traveling, the direction of motion whereof is such that the fuel is systematically admitted at the front of the furnace and carried toward the rear thereof, the draft-opening of the furnace being at the rear, so that'the draft-entrance is opposite to the feed-opening,whcreby the fun nace is uniformly supplied and the fire equably maintained throughout the length of the grate.

It also consists of other details of construction, as will be hereinafter set forth.

Referring to the drawings, A represents a series or number of grate-bars, a, jointed one to another, forming an endless grate, which is supported at opposite ends on rollers or drums B, of polygonal form, and the part which is above andintermediatc of its ends on stretchers O, the hearing of said rollers and the stretcher-s being sustained on masonry, brickwork, or other suitable supports, the boiler or other object to be heated being likewise properly sustained or supported- In the front wall ofthe masonry, just above the upper part of the grate, is a throat, D, which forms a communication with the combustion-chamber of the furnace and permits the passage of the grate thereinto. The grate is extended beyond the front wall of the masonry, so as to form a hearth, E, the sides whereof have guards F, for preventing lateral displacement of the fuel placed on the hearth, said guards being secured to the masonry, but may be otherwise properly held in position.

Guided in the front wall of the masonry is 5o a sliding gate or door, G, which is adapted to move toand from the top of the grate, so as to cover and uncover the throat D, said door having fitted to it vertical screw rods or bolts H,whieh are geared together,whereby by the operation of a crank or hand-wheel, b, attached to one of the shafts of the gearing, said rods may be rotated, and the door G thereby raised and lowered.

To the axis or hearing of the rear roller, B,

is attached a worm-wheel, J, with which engages a worm, K, the shaft K whereof is properly mounted on the masonry or support of the grate, and carries a ratchet, L, the operating-pawl M whereof is hung on an elbowlever or angular arm, N, which is fitted loosely on the shaft K, and receives motion from a shaft, P, through the medium of an eccentric, Q, on said shaft, and a connecting-rod, B, said shaft having power imparted to it in any suitable manner, and the lever N being slotted, as at (l, to receive the attaching-bolt e of the rod R, whereby the throw of the pawl M may be adjusted.

It is evident that when the grate is employed in the furnace of a steam-boiler the shaft P. may be operated by steampower through the medium of pulleys, belts, or other suitable de vices connected with the engine or machinery driven thereby.

S represents a door of the furnace at the rear thereof, above the grate, the same having its frame secured to the masonry, and to said frame, or another suitable support adjacent thereto, is hinged a chute or scraper, T, which overhangs the top of the grate, and has one end in contact therewith, said end projecting toward the front of the furnace.

The operation is as follows: The fue1,which may be bituminous or anthracite coal, shavings, refuse, &-c., is placed on the projecting front ofthc grate or hearth, the door G raised, and power communicated to the arm N, so as to raise and lower the same, the effect whereof is to cause an intermittent motion of the shaft K through the medium of the pawl and ratchet M L. This operates the worm and worm-wheel K J or other suitable gearing which may be employed in lieu thereof, and rotates the drum connected with said wormwheel, whereby the grate is caused to move or travel in a gentle and uniform manner, the direction of motion being from the front to the rear of the furnace. The fuel is carried by the grate through the throat D, the stream or quantity being regulated by the door G, which, as has been stated, is adapted to be raised and lowered,and thus adjust the extent of opening and closing of the throat. The draft of the furnace is from the rear thereof, and after the fire is fairly started and the fuel V begins to be consumed a fresh supply of. fuel is carried into the furnace by the traveling grate in a steady manner and to uniform ex tent, and the bed of fuel is constantly fed with fresh fuel, whereby an equable fire is maintained throughout the length of the grate or furnace. The ashes as formed fall or are poked through the grate-bars into the pit bethe fire is not checked or cooled down by the adm'ssion of cold air during the process of supplying fresh fuel, as by hand firing. It will also be seen that on account of the heat or flames passing over the fresh automatic ally-supplied fuel it will ignite and burn from the top, and thereby instantly mix with aid consume the smoke and gases at the point of emission from bituminous or other gaseous or snioky fuel, and the evaporative power in the case of the boiler for the coal burned must necessarily be greater than if the gases had. escaped past the boiler unconsumed.

The door S also permits access to the fur naceat. the rear thereof and may be employed as a damper for the fire.

Owing to the exposure of the door G to the flames or products of combustion generally, said door is made hollow,or of box form, and lined with fire-brick or other suitable material, so that the latter is presented toward the throat D, whereby the door is protected and burning of the mass of fresh fuel on the hearth prevented.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. An endless traveling grate, in combination with the inclined guide and scraper, a door above said scraper, and a draft-entrance below said grate, the scraper, door, and draft en! rance being at the rear of the traveling grate, substantially as and for the purpose set forth.

2. An endless traveling grate having one end extended in front of the furnace, forming a hearth, a supply-throat in front, a draft-entrance in the rear, and an inclined guide and scraper overhanging the rear end ofsaid grate, substantially as and for the purpose set forth.

C H ARLES H. HOLT.

Vitnesses:

JOHN A. \VIEDERSHEIM, A. P. GRANT. 

